CS208, Monday 10 Jan 2022

Skills to be practicing

• Unix
• C
• writing integers in binary, octal, and hexadecimal

Questions about Starting C assignment

• ??

Brief note on sizes

• sizeof
• sizeof(char *)
• size_t

Queues in C assignment

• Goals: pointers & error handling
• Walk through the testing/building infrastructure
  • Code
  • make test
  • fix q_new, then rerun make test
  • ./qtest to play with your code as you proceed
• Advice
  • Get started right away
  • One function at a time, from the top
  • Check return value from malloc every time
  • Check parameters for NULL every time
  • Write "make_node" and "free_node" functions when you get to inserting and removing
• Style issues
  • The original lab authors' naming style (yuck)
  • One-liner ifs, elses, whiles, etc.: still use braces!
  • Brace placement

Integers

• want to practice your hexadecimal? here's your game: Flippy Bit and the Attack of the Hexadecimals From Base 16
• binary is the real data, octal/decimal/hexadecimal for writing them more conveniently; an integer is an integer, no matter what notation you use to represent it
• short, int, long
• bytes of an int in memory
• byte order, also known as "endianness"
  • Jonathan Swift's "Gulliver's Travels"
  • eggs, big-endians, and little-endians
  • big/little-endian integers

Negative integers

• Signed magnitude
• Two's complement